What Is Chronic Spontaneous Urticaria (Hives)? Symptoms, Causes, Diagnosis, Treatment, and Prevention

You’re probably familiar with hives — intensely itchy welts on the surface of the skin.

For most people, these welts disappear in 24 hours or less, without leaving a mark. But when the welts appear spontaneously (with no known cause) and linger for longer than six weeks, they’re known as chronic spontaneous urticaria (or chronic idiopathic urticaria).

• Acute spontaneous urticaria Hives that occur spontaneously but fade within six weeks.
• Chronic spontaneous urticaria (CSU) Hives that occur spontaneously and linger for six weeks or longer, either continuously or intermittently. This is also known as chronic urticaria and chronic idiopathic urticaria.
• Chronic inducible urticaria (CIndU) Hives which occur in response to a trigger, such as heat, exercise, or scratching.

The symptoms of chronic spontaneous urticaria include:

• Patches of welts (called wheals) on the body, especially on the arms, back, chest, face, and legs

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• Itchiness (pruritus)
• Painful swelling (angioedema) around the cheeks, eyes, or lips
  

These welts may appear red or pink on white skin. On brown or Black skin, hives can appear the same color as the surrounding skin, purplish, or slightly darker or lighter in hue. When you press on the welt, it tends to “blanch,” or fade in color.

Usually, there’s no known cause of chronic spontaneous urticaria, but hives may develop when a trigger — such as heat or sunlight — activates certain cells in the immune system called mast cells.

When that happens, the skin releases chemicals such as histamine, a compound that causes itching and swelling.

• Cold or heat
  
• Medical conditions, such as thyroid disease, infection, cancer, and allergies
  
• Pressure on the skin, from a backpack or bra strap
• Sunlight
• Vibration, such as jogging

While people often believe that hives are a response to stress, “Stress can lower the threshold for developing hives, but it’s not the underlying cause,” says Mark Aronica, MD, a physician who specializes in asthma and allergic disorders in the department of allergy and clinical immunology at Cleveland Clinic in Ohio.

Similarly, even though chronic hives are rarely triggered by allergies, people who have allergies are a little more likely to have an episode of chronic urticaria at some point in their lives, says Dr. Aronica.

In most cases, doctors evaluating a person with acute urticaria (lasting less than six weeks) make a diagnosis based solely on a physical exam and an assessment of symptoms.

But when hives become chronic (lasting longer than six weeks), physicians typically order a comprehensive medical workup.

A physician might perform a skin biopsy or order blood work if the hives are persistent or linked to additional symptoms, such as fever, individual hives that last for days at a time, or hives that are painful or associated with bruising.

The treatment for chronic spontaneous urticaria can vary from person to person and often depends on the severity of the hives. While anti-itch medications are often the first-line treatment option, some people may not need to take anything at all.

“If I have a patient who is having intermittent hives — they’re getting an outbreak once a week or a couple times a month — taking a medication every single day for this may not be the appropriate strategy,” says Aronica.

Medication Options

Part of the decision to treat or not treat chronic hives largely depends on the person, says Aronica. “That decision can depend on how the hives are affecting [the person] and what they want to accomplish.”

The standard therapy for people having frequent episodes of chronic hives is a long-acting, nonsedating antihistamine, many of which are available over the counter.

Histamine (H2) blockers: Also called H2 receptor antagonists, histamine blockers are injected or taken orally. Examples include cimetidine (Tagamet HB) and famotidine (Pepcid).

Anti-inflammation medications: Oral corticosteroids, such as prednisone (Deltasone, Rayos), can help with symptoms such as discoloration, itching, and swelling but shouldn’t be used long term.

Asthma drugs with antihistamines: These medications can help with hives and itching in some people when used together with antihistamines. Examples are montelukast (Singulair) and zafirlukast (Accolate).

Monoclonal antibodies: The drugs omalizumab (Xolair) and dupilumab (Dupixent) may be given as injections for difficult-to-treat chronic hives.

Immune-suppressing drugs: These medications — including cyclosporine (Neoral, Sandimmune), methotrexate, and tacrolimus (Prograf, Protopic) — work by suppressing the immune system and are usually limited to short-term use.

Alternative and Complementary and Integrative Therapies

Taking a vitamin D supplement may offer some relief for people with chronic urticaria, because a vitamin D deficiency may be associated with a slightly higher risk of urticaria, says Aronica. “In some cases, if you address the deficiency, the hives may improve,” he says.

Because no one knows what causes chronic idiopathic urticaria, there is no clear way to prevent the condition.

Lifestyle Changes for Chronic Spontaneous Urticaria

• Wear comfortable, loose clothing.
• Avoid soaps and lotions with harsh chemicals.
• Take a soothing bath and then apply fragrance-free lotion or anti-itch cream to your skin.

Should You Try a Low-Histamine Diet?

Some foods — such as seafood, fermented foods (aged cheeses, dry sausage, fermented soy), tomatoes, eggplant, spinach, and avocado — contain higher levels of histamine than others. So it’s thought that limiting or avoiding these foods might help alleviate the symptoms of chronic spontaneous urticaria.

Usually, chronic spontaneous urticaria lasts for about three to five years, with up to 80 percent of people achieving remission within the first 12 months of developing symptoms.

Chronic urticaria is often a “one and done” situation, says Aronica. “That ‘one time’ can last for a couple months or couple years,” he says, “but then they never experience it again.”

The complications of chronic spontaneous urticaria can include:

• Angioedema: The eyes, lips, and tongue can swell. Rarely, the throat also swells, which could cause difficulty breathing and may be life threatening, says Aronica.
• Anxiety and depression: Chronic hives can be very uncomfortable — and highly visible — which can cause emotional distress for some people, says Aronica.
• Pruritus: The intense itching from chronic hives can affect quality of life.

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A small subset of people with chronic urticaria may develop an autoimmune disorder, though the risk is small, says Aronica.

• Chronic spontaneous urticaria can cause itchy welts to appear on the skin. There’s no known cause for why they appear.
• Some treatments for chronic spontaneous urticaria include antihistamines, immune-suppressing medications, and monoclonal antibodies.
• For many people, chronic spontaneous urticaria often goes into remission within one year.